DC On-Line (Chiropractic Research)

By Brian Sutton, DC

A study published in the Journal of the American Medical Association1 reports that patients who frequently use asthma inhalers containing steroid drugs are 44 percent more likely to develop glaucoma.

This research was done using the insurance records of 39,000 elderly patients. The effect was seen when patients used the drug four times daily for 3 months or longer.

1. JAMA, March 5, 1997.

Medical Patients Don't Outgrow Asthma Anymore

Medical asthma experts are now saying that asthma should no longer be considered a reversible disorder. At a medical conference in San Francisco,2 researchers said that their studies indicate that asthmatic lungs worsen as time goes on, and report that lung function declines five times faster in aging patients. Experts at the meeting3 said that patients experiencing more than one attack per month should be taking daily doses of a steroidal inhaler as a preventive measure.

2. Reported by the United Press, February 23, 1997. 3. Including Dr. Scott Yates of the Jacksonville Naval Hospital.

Self-Exams Flop in China

An attempt to quantify the effectiveness of breast self-exams in China has failed to show any value in the procedure. A study of 267,000 women published in the Journal of the National Cancer Institute4 found that intensive training had no significant impact on mortality or detection of breast cancer. Researchers thoroughly trained half the women in self-examination techniques and checked their proficiency every six months of the five-year program. The group was also "tested" using a plastic breast model. Even though they were able to detect lumps in the model more often than non-trained women, they ultimately fared no better when it came to detecting cancer in themselves. They did discover benign tumors twice as often, though. The researchers intend to continue the research another five years.

4. JNCI, March 4, 1997.

Pig Virus

One of the concerns about the concept of raising pigs to supply organs for human transplant recipients is the potential for inter-species viral transmission. Now a report in Nature Medicine5 is stirring up even more interest in that area. Researchers from the Cancer Institute of London working with PERV-PK, an ancient virus that has incorporated itself into the DNA of pigs, have found it can infect human cells. The virus is related to those that cause leukemia in cats and mice. The virus, as it is released from pig cells, is sought out and destroyed by human immune components. However, when the virus infects human cells, subsequent generations do not appear to trigger much of an immune response. The group says the virus is able to infect human kidney, lung, muscle, and immune cells. Genetic engineering has been suggested to counter the problem, but this may be difficult since up to 50 copies of the virus can be found at various locations in any given pig's DNA.

5. Nature Medicine, March, 1997.

Circumcision and Pain Tolerance

A second study of the effects of circumcision of boys on pain tolerance later in life has been completed at the Toronto Hospital for Sick Children. Results were similar to the earlier study (as reported in this column on April 10, 1995) in that circumcised boys were significantly more sensitive to painful stimuli a number of years later. This work, though, also analyzed a group that had a topical anesthetic applied before the surgery. This seemed to lessen the effect, lending support to the theory that some kind of neurological "priming" of pain interpretation is responsible.6

6. The Lancet, March 1, 1997.

Keep Walking

A letter to The Lancet7 reports a possible way to predict which elderly patients are more likely to fall and injure themselves. Swedish physiotherapists have observed that frequent fallers are more inclined to stop walking when they talk. These are people who, while out for a stroll, will stop walking when they wish to say something. Conversely, people who are at ease talking while they continue to walk appear to be much steadier on their feet. Armed with this new insight, the researchers hope to improve these older patients' chances of remaining upright by encouraging them to walk and talk at the same time. Sounds like an invitation to trouble to me!

7. The Lancet, March 1, 1997.

Limited Thinking Limits Benefits

Estrogen replacement therapy has been touted as a great way to reduce a woman's risk of coronary artery disease. However, because estrogen also seems to raise cancer rates, another hormone (progesterone) is prescribed in an attempt to counteract this effect. A synthetic version of progesterone called MPA is often used. However, when researchers tested this combination in monkeys, they found that the MPA canceled out any beneficial effects of the estrogen; natural progesterone did not. Apparently, there is a difference.8 The researchers suggest that by using this popular combination, doctors are unwittingly sabotaging any perceived benefit of the drug therapy.

8. Nature Medicine, March, 1997.

Bone Strength as Cancer Indicator

A new study completed by Boston researchers supports earlier work correlating bone strength to breast cancer in women. Women with the strongest bones seem to be three and one half times more likely to suffer from breast cancer than their osteoporotic peers.9 The reason is thought to be estrogen, long suspected of increasing the risk of breast cancer but often used to treat osteoporosis. This study looked at post-menopausal women who had received bone density tests and reviewed their breast cancer rates for the subsequent 20 years. One of the authors of the study says that the estrogen responsible is "not the kind that doctors give you when you enter menopause, but the kind that is naturally occurring in the body during a woman's pre-menopausal years."10 I'm not convinced.

The University of California at Berkeley has been studying the effects of air pollution on the skin. Researchers there have concluded that dermatitis occurs much more readily in areas of high pollution. They discovered that ozone depletes vitamin E from the stratum corneum, an upper layer of the skin. After a 2-hour exposure to ozone levels approximately twice that often occurring in Los Angeles, vitamin E content decreased by 25 percent in test mice. The researchers suggest that destruction of the vitamin leads to breakdown of skin lipids which in turn increase irritation of the skin.11

11. Reuters, February 25, 1997.

Obesity by City

A study12 released by the Coalition for Excess Weight Risk Education ranks 33 American cities by their percentage of obese citizens. The heaviest city was New Orleans, with 37.5 percent of its citizenry classified as heavyweights. Denver was the lowest at 22.1 percent. The paper blames the overweight on -- and this may surprise some people -- overeating. New Orleans is known for its plentiful restaurants and culinary debauchery, while Denver residents are more likely to be outdoors and health food enthusiasts.13

12. The National Weight Report. 13. Associated Press, March 4, 1997.

Heart Attacks and Vitamin C Deficiency

A Finnish study of 1,600 middle-aged men suggests that a lack of vitamin C may be a contributing factor to heart attacks. At the start of the study, all the men were judged to be free of heart disease. However, in the subsequent nine years, 13 percent of those men deficient in vitamin C suffered heart attacks. Only 4 percent of men who had adequate blood levels of the vitamin were stricken. The same researchers also did a smaller study to see if vitamin C supplements would help, but found little effect. They concluded that one probably must consume whole foods to benefit from the vitamins contained therein.14

14. Reuter News, reporting on the work of Jukka Salonen at the University of Kuopio, February 28, 1997.

DHA in Formula?

One of the current hot items at the FDA offices now is the question of the fatty acid DHA. DHA is required for brain and eye development in infants and is available in breast milk, fish, and marine algae, among other sources. It is not found in any of the commercial infant formulas sold in the United States.15 Consumer advocates want the FDA to require its inclusion, but manufacturers aren't convinced it's worth the extra 10 cents per can to add it. Researchers feel it is especially important in premature babies and may be a major factor in the differences seen between breast-fed and bottle-fed infants. One study also found that DHA-supplemented infants develop good vision faster.16

15. Associated Press, February 23, 1997. 16. Visual research done by Dr. Susan Carlson of the University of Tennessee, Memphis.